


The Three of Us

by Anonymous



Category: Supernatural
Genre: Cunnilingus, Dirty Talk, F/M, Hand Jobs, M/M, Masturbation, Plot What Plot/Porn Without Plot, Vaginal Sex, Voyeurism
Language: English
Status: Completed
Published: 2020-04-05
Updated: 2020-04-05
Packaged: 2021-02-28 22:27:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,243
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23414560
Author URL: https://archiveofourown.org/
Summary: Dean and Castiel are happily married, but for some time Dean's been hooking up with his husband's sister whenever she stays over at their house. He knows he's messed up but he can't help himself, turned on by cheating and how wrong it is. As soon as Castiel leaves the house to go to his job and Dean and Anna gets a moment alone, they're all over each other. But what happens when Castiel forgets his lunch?
Relationships: Anna Milton/Dean Winchester, Castiel/Dean Winchester
Kudos: 35
Collections: Supernatural Anon Kink Meme





	The Three of Us

**Author's Note:**

> Moving my fills to AO3, originally posted [here](https://spnkink-meme.livejournal.com/107745.html?thread=40665057#t40665057).

The door has barely had time to close behind Castiel before Anna is walking up behind Dean, moving her arms around his waist, running her hands over his chest.

"I thought he'd never leave..." Anna says, letting out a sigh as she presses her forehead to the back of Dean's shoulder. "I've missed you."

Dean can't help himself. He knows it's wrong to cheat on his husband, especially with Castiel's sister, but there's something so intoxicating and enthralling about it. Every time he goes in for a taste of the forbidden fruit, he wants more of it.

"Bet you have," Dean mumbles and grabs one of Anna's hands and moves it to his mouth. Her hands are soft, her fingers long. They feel feather-light and fits easy in his own. They are delicate in a whole different way than his owns, or Castiel's. Dean kisses her palm, and up over her fingers.

"Come on, Dean. He's been gone for two minutes already. What's taking so long?" she says with that impatient and needy tone of her voice that makes her sound an awful lot like Cas. Or maybe it's the other way around. It sends chills down Dean's back as a pleasant shiver makes its way through his body.

"What? I'm enjoying this. Let me have this moment, alright? I never know when the next time I get to spend time with you is," Dean says.

He turns around then to look at her.

Anna is wearing one of his plaid shirts. It's big on her, reaches just beneath her ass. The shirt is unbuttoned, showing off the cute, baby-blue underwear she's been sleeping in. Dean eyes her up and down, taking in the view for once. He wants to remember this, every moment of it.

"Exactly," Anna starts, pushing her palms over Dean's bare chest, "So make the most of it."

Without further notice, Anna leans in close and stands up on her toes. She pushes her lips to Dean's, her breath smells like the peppermint toothpaste she's nicked from his and Cas' tube, her soft lips tastes like it as well. Dean welcomes her kiss and eagerly parts his lips when he feels the first push of her wet tongue run against the seam of them. Anna kisses him deeply, as if she's been waiting forever to taste him. Dean never has been able to understand how she can kiss with such fervor and elegance at the same time, her tongue licking its way into his mouth.

Anna's hands are on Dean's chest, her soft fingers rub over his nipples and she works her hips against his. Dean busies himself with pushing his plaid shirt off her shoulders and he notices somewhere in the back of his mind that she kicks it back behind herself with her feet, and it slides over the floor with a soft sound as he toys with the straps of her bra.

"Want you," Anna mumbles against his mouth between kisses.

Dean rubs his hands over her skin, down over her breasts. "You'll get me, baby. Be patient."

She nips at his lips. "With you?" Anna huffs out a snort. "Never."

Dean raises his eyebrows in response to that and unhooks her bra with one hand then gives her a triumphant smirk and cocks up an eyebrow.

"Like what you see, Winchester?" Anna asks with a similar smile on her face, shaking her head a little to move her hair back over her shoulders, posing subtly to let Dean look at her properly.

She's gorgeous, so fucking beautiful as she stands there, all the confidence in the world. That fiery passion, her red hair, her soft, pale skin and her perky and perfectly round breasts. Dean takes all of it in, thinks of how nicely her tits will feel in his hands later, how he'll bite and suck on those nipples until she's whining in pleasure. He looks at Anna's long legs and he wants to spread them apart, run his hands over her thighs and bury his face between them, breathe hot over her stomach and lick over her luscious lower lips until she's soaked through her panties.

Dean swallows and takes a breath. "Oh hell yes.”

Anna counters him with a wiggle of her eyebrows, and then Dean's hands are on her, swiftly lifting her up off the floor and setting her down on the kitchen island.

"Here?" Anna asks. There's not a hint of hesitance in her voice, only curiosity and anticipation.

"Yeah," Dean says as he presses his hips against her, leaning close to the island while she wraps her legs around his waist. "Been awhile."

His mind goes to memories of some of their first times together. Of drunken clumsiness and the badly lit kitchen, of swollen lips and sweaty bodies against the cold granite counter top. Of held-back giggles and stifled moans. Dean remembers sliding into her for the first time, how hot and tight she'd been, how he'd had to press a hand over her mouth to keep her from waking Cas up. He'd never known the idea of Cas catching them would be so enticing.

"Come on, Dean," Anna says, bringing his mind back to the present. She's leaning back on the counter top, resting on her elbows. "Bet you have a million ideas running through your mind right now."

"Bet I do," Dean says, grinning, his dick half-hard already from the view alone.

He rubs his bulge against Anna's panties where their groins meet.

"I want you to eat me out," Anna says, matter of fact as if she's talking about the weather, as if it's the most obvious thing in the world. And it is. Dean's a master at eating out. He loves every part of it.

Anna doesn't have to ask twice, Dean's already kissing his way down from the corner of her mouth, over her jaw and neck and chest. He stops over her breasts, takes one of her nipples between his teeth, teases her for a moment before sucking onto it, flicking over the small nub with his tongue – a preview of what's to come.

"Last time I checked, my pussy was still between my legs," Anna taunts with an impatient grunt and kicks her heels softly against Dean's back.

"Hey!" Dean pulls his head from her chest, furrowing his eyebrows at her. "Language, or do you want to get a spanking in too, huh?" Anna starts to open her mouth, a wicked look on her face, but Dean cuts her off. "Never mind, don't answer that."

Dean curls his fingers into the waistband of her panties instead, and Anna lifts her hips up as he slides her underwear off down her legs and lets them join her bra and shirt on the floor.

"Come on, up," Dean commands, and Anna scoots back, placing her feet on the flat surface, exposing her beautiful thighs and the folds between her legs.

Dean leans down again, lets Anna move her legs over his shoulders as he moves himself in closer to her, pressing his lips against her skin, leaving a trail of bite marks and hickeys over her thighs on his way as she giggles excitedly.

Finally, Dean rubs his hands over her hips and presses his mouth to her folds, kissing experimentally and softly against her skin a few times, before finally pushing his tongue inside. He tenses the muscle in his tongue, sticks it inside her as far as he can and then he licks, long and deep until Anna's thighs are quivering. He circles around her clit, flicks his tongue at it teasingly for a few seconds before he licks and laps eagerly over her wet folds and downwards. Dean moves his tongue carefully over her perineum, and further back still, until the soft, warm press of his mouth moves over her tight hole.

Anna's breaths are coming out loud and fast, and she's whimpering and mumbling.

"More, oh God please, _more_."

"I'll take it you like it?" Dean snickers, a triumphant grin on his face at having reduced Anna to a moaning, babbling mess.

"Shut up." Anna pants and removes her legs from around Dean's shoulders, allowing him to straighten up. His chin and lips are glistening with her delicious juices. "Let me clean you up," she says.

They kiss deeply, somewhat sloppily, and it doesn't help when Dean puts a hand between Anna's legs, rubbing gently over her clit and then dips two fingers deep into her.

"Not enough," Anna says against his lips, and Dean finger fucks her faster, trying to rub that spot inside her walls that will make her see stars.

He loves this, loves the way she clenches around his fingers, loves the breathy sounds and moans that fills the kitchen. Loves how dirty it feels, how he knows he will be having dinner here tonight with his husband, in the same kitchen where he fucked Cas' sister.

"No, Dean," Anna shoves at his hand and Dean removes it instantly. "Need you," she says, eyes blown with lust.

"Need what?" Dean teases, biting his bottom lip, eyebrows raised expectantly as he awaits her answer. "Come on, baby, tell me what you need."

Anna leans forward and begins to palm Dean's hard dick through his boxers.

"Need this, need your cock."

***

Anna hops down from the kitchen island and turns around. Dean moves in quickly behind her, spreading her legs as Anna leans forward on her arms, bending over the counter top.

"Yeah?" Dean asks, pushing his hips flush against her naked ass. "You want this?" His cock is hard, and he rubs himself against her cheeks, his dick jerking and jumping under the fabric of his boxers.

"Want it, yeah," Anna says with a moan, standing up on her toes. "Want you to fuck me. Right here."

Dean works himself against her ass for a moment, then he slides his boxers down just enough to let his cock spring free. He wraps a hand around himself, holding the cock head in his hand and watches as pre-come bubbles out from it. He moves his hand over the head, rubs it down over his cock to make it slicker.

"Where you want it, baby?" Dean asks, leaning forward, draping himself across Anna's back. His cock nudges against her ass.

"Inside," she says, then Dean puts two fingers into her mouth, and she sucks on them, getting them nice and wet.

"Inside where, sweetheart?" Dean coos, moving his spit-slick hand down to her breasts to play with her nipples. His cock slides between her ass cheeks when Anna pushes back. It's the most delicious thing.

"In my pussy," Anna rubs her ass back against Dean's crotch. "Need you inside me, Dean, please."

She doesn't have to wait any longer, Dean is as eager to get inside her as she is. He aligns himself against her entrance, the head of his cock disappears easily between her lips and then, with a moan, Anna pushes back to meet Dean's hips as he moves forward, sliding his cock all the way inside of her until he bottoms out.

"Finally," Anna says, dropping her head and chest to lie flat against the surface. "Now move."

She doesn't have to ask twice.

Dean grabs hold of her narrow hips, digs the tips of his fingers into the juncture of them, and pulls himself out far enough that his cock almost leaves the warmth inside of her, and then he slams back in hard, pushing Anna up higher against the counter top. Part of him can't wait to see the bruises on her hips and thighs from the hard edge of the granite later.

Anna huffs out a strained moan as if Dean is fucking the air right out of her lungs. Her toes barely reach the floor when Dean lifts her up by the hips to align himself better, and he pushes back in inside of her with hard, precise thrusts.

It's not the same as fucking Cas. Cas is filthy on a whole other level. He's an animal, unlike his sister. Anna is soft, graceful, feather-like. Dean loves how he can just move her easily, fit her snugly against himself and push into her as if it's the easiest thing in the world. She's so wet and warm, fits around his body like it was meant to be.

"Fuck you feel so good," Dean pants, sliding his cock deep into her.

Anna moans loudly in response. "So do you."

They continue for a few minutes until Anna demands that they continue somewhere softer, and then she grabs Dean by the arm and drags him with her up to his and Castiel's bedroom.

"Here? You sure?" Dean asks as Anna crawls up on the bed, legs spread obscenely.

"Want to ride you. You don't want that?" She tilts her head to the side, red hair falling down over her soft breasts.

Dean can feel his mouth watering.

"Yeah, yeah of course."

When Dean lies down, Anna climbs on top of him and sinks down easily onto his cock, throwing her head back in pleasure as his cock rubs against her spot over and over. Dean wets his fingers and uses one hand to play with Anna's nipples, the other one placed firmly on her hips as she bounces up and down in a steady rhythm.

It's then, as Anna's voice grows louder, and Dean can feel the straining hot pull of muscles as his own orgasm draws close, that he catches something in the corner of his eye. Right behind Anna, looming in the doorway, is Cas.

For a second, Dean is flooded with panic and he grits his teeth hard, clenches his jaw as Anna pushes down particularly rough on his cock as she comes, yelping loudly.

Dean watches Castiel steadily through his hooded eyes, biting down on his bottom lip as Anna keeps rolling her hips slower, whispering dirty words that fills the air between them.

Strangely, from what Dean can see, Castiel doesn't seem angry. There's something stern in the tenseness of his eyebrows and mouth, but he doesn't look like he's going to barge in on them, and he hasn't made a sound yet.

He's covered partly by the red locks of his sister's hair as she grinds herself down against Dean, working her hips through the aftershock of her own orgasm, drizzling wet and warm around him.

Then Dean sees it. The small flush on Castiel's cheeks, the glint in his eyes. Dean knows that look. He sees it a couple of times every week.  
  
"Come on baby," Anna coos, "I've got you. You make me so wet, _fuck_ honey, your cock is so nice. Want you to come inside me. Please baby, come on Dean, fucking fill me up. I want to feel it."  
  
And Dean can't help himself. He watches Castiel, the strain in his pants, the flush on his cheeks. He feels the slippery warmth of Anna's cunt around his cock as she continues to roll her hips in sweet, hard stutters, and the hotness deep in Dean's stomach explodes.  
  
It's the most intense orgasm he's had in weeks. His vision going out for a second as Anna milks all of his come out of him before she climbs off and disentangles herself from his body.  
  
When she slumps down next to Dean, Castiel is gone.  
  
Dean catches his breath, wipes the sweat from his forehead and just lies there for a good few minutes before he sits up.  
  
"Where're you going?" Anna mumbles from the pillows, a hand coming up to curl around Dean's bicep.  
  
"Just... Need a drink. That was intense," he says with a chuckle.  
  
"Mhm. It was, wasn't it?" Anna laughs and nudges Dean in the side. "Get me one too, would you?"  
  
"Sure thing."  
  
Dean smiles at her and strokes a hand over her hair before standing up and leaving the bedroom to search for Cas.  
  
Dean finds him after barely a minute.  
  
"Cas–" Dean starts as he sees the figure of him slumped over awkwardly in the dark in the back of the laundry room, whimpering. "Cas, fuck, man I'm sor–"  
  
Dean stops himself mid sentence, two steps into the dark room.  
  
In the back of the laundry room, stood half-bent over the washing machine, Cas is whimpering quietly, but Dean realizes when he sees the motion of his arm, quick and furious over his crotch, that he's not crying.  
  
Dean blinks at him, mouth drying up instantly at the sight. In the light from the hopper window he catches the outline of Castiel's cock, angry and red, the head already glistening with precome between his fingers.  
  
"You're... You're not mad?" Dean asks, licking his lips and taking a step closer, his heart beating like a drum in his chest.  
  
"I, ugh, I forgot my lunch," Castiel bits out, words slightly muffled as his face is pressed half into his arm where he leans against the washing machine.  
  
"Okay..."

A million thoughts run through Dean's mind.  
  
"Dean, _please_ , talk to me." Castiel says before Dean has time to panic, and there's that raggedy, wrecked voice.

Dean recognizes it immediately, putting one plus one together and hurries over, putting a hand on the small of Castiel's back.  
  
"Yeah, okay, babe. What you wanna hear?"  
  
Castiel groans. "Anything."  
  
"You want to hear about what you just saw?" Dean leans in close, his lips grazing Castiel's ear as he whispers to him. "About how I fucked your sister, and I fucked her good? You couldn't stop watching us, could you? You liked it."  
  
"Yes, please Dean, continue."  
  
Dean smiles, licking a stripe over Castiel's neck.

"I bet you feel so ashamed about it, so _dirty_ , like the dirtiest slut in the family, getting all hard and embarrassed by watching your sister ride my dick. She's desperate for it, you know, can't get enough of it. Must run in the family..."  
  
Castiel whimpers again, alarmingly loud. Dean bites his neck gently, as a warning. "Shh, don't want her to find out that you know about us, right? Unless you want to turn this into a family affair."  
  
Dean moves his hand around to Castiel's crotch and pushes Cas' hand away so he can take over for him. He curls his fingers around the thick shaft of his cock and pumps hard, up and down, rubbing his thumb over the slit a few times.  
  
"Sometimes, she takes it up the ass. Oh man, you should see that. She's crazy for it. Loves when I eat her out too. Can spend all night licking out that sweet pussy until I'm covered in her juices. Bet you didn't know that, huh? How many times have you come up and kissed my mouth and tasted her..."  
  
Castiel comes quietly, nothing like the animal he usually is with Dean, his breath stopping and his body seizing up as his cock spits and splutters all over Dean's hand.  
  
"There's my boy," Dean whispers, kissing his neck as he tugs the last drips of come out of Cas. "Jesus. We gotta do this again sometime."  
  
Castiel turns his head and glares at Dean, but there's a wicked smile playing on his lips, and Dean's heart skips a beat in his chest as he realizes he's married into the most fucked up and amazing family he could have ever dreamed of.


End file.
